1. Field of the Invention
The present invention relates to a movable coordinate inputting apparatus, and in particular to a movable coordinate inputting apparatus such as an input apparatus adapted to a mouse or a touch panel for a personal computer.
2. Description of the Background Art
FIG. 1 illustrates the construction of a mouse as an example of a conventional movable coordinate inputting apparatus. As shown therein, a conventional apparatus for inputting a movable coordinate when a coordinate input apparatus 1 is moved on a certain surface includes a ball 2 moved based on a rotation of the coordinate input apparatus 1, an X-direction shaft 3 contacting with the ball 2 and rotating based on an X-direction component of a rotation force of the ball, a Y-shaft direction shaft 4 rotating based on a Y-direction component of a rotation force of the ball 2, a X-direction circular plate 5 fixed at one end of the X-direction shaft 3, and a Y-direction circular plate 6 fixed at one end of the Y-direction shaft 4.
In the above-described conventional movable coordinate inputting apparatus, the ball 2 is rotated based on a movement of the coordinate input apparatus 1. The X-direction component and Y-direction component of the rotation speed and rotation direction of the ball 2 are transferred to the X-direction shaft 3 and the Y-direction shaft 4, and the X-direction circular plate and the Y-direction circular plate 6 are rotated.
FIG. 2 illustrates the X-direction circular plate 5 of FIG. 1 in the direction of the arrow A. The X-direction circular plate 5 includes a plurality of slits 7 formed at a regular distance for transmitting light therethrough, and a pair of photo sensors 8 and 9 for detecting the light transmitted the slits 7. The photo sensors 8 and 9 are installed so that one of the same is deviated from the position of the slit 7 when the other of the same is overlapped with one of the slit 7.
FIG. 3 illustrates wave forms of the photo sensors 8 and 9 when the X-direction circular plate 5 of FIG. 2 is rotated. As shown in FIG. 2, when the X-direction circular plate 5 is rotated in the clockwise direction(normal rotation), the photo sensor 8 outputs a pulse of a wave form as shown in (1) of FIG. 3, and the photo sensor 9 outputs a pulse of a wave form as shown in (2) of FIG. 3. In addition, when the X-direction circular plate 5 is rotated in the counter clockwise direction(reverse rotation) as shown in FIG. 2, the photo sensor 8 outputs a pulse of a wave form as shown in (3) of FIG. 3, and the photo sensor 9 outputs a pulse of a wave form as shown in (4) of FIG. 3.
Therefore, it is possible to check the rotation speed of the X-direction circular plate 5 based on the period T of the above-described pulses. In addition, since the photo sensors 8 and 9 are arranged in the above-described method, when the X-direction circular plate 5 is rotated in the normal direction, in the case that an output of the photo sensor 8 is changed from a high level to a low level, the output of the photo sensor 9 is a low level for thereby forming a certain phase difference. When the X-direction circular plate 5 is rotated in the reverse direction, in the case that an output of the photo sensor 8 is changed from a high level to a row level, the output of the photo sensor 9 is a high level for thereby a certain phase difference. Therefore, the rotation direction of the X-direction circular plate 5 is checked based on the above-described phase difference, and the rotation speed and rotation direction of the Y-direction circular plate 6 are detected.
The rotation speed and rotation direction of the X-direction circular plate 5 are X-direction components of the rotation speed and rotation direction of the coordinate input apparatus 1. In addition, the rotation speed and rotation direction of the Y-direction circular plate 6 are the Y-direction components of the rotation speed and rotation direction of the coordinate input apparatus 1. Therefore, it is possible to detect the moving speed and moving direction of the coordinate input apparatus based on the above-described components.
FIG. 4 illustrates wave forms for describing a measurement of the moving speed and moving direction of the coordinate input apparatus 1 using the pulse wave forms as shown in FIG. 3. (1) of FIG. 4 illustrates an output pulse of the photo sensor 8, and (2) of FIG. 4 illustrates an output pulse of the photo sensor 9. The moving speed and moving direction of the coordinate input apparatus 1 are obtained based on the following method. First, the numbers of the pulses(the output pulse of the photo sensor 9) are counted at the periods of SO, S1, S2, Snxe2x88x921, Sn+1.
The thusly obtained number of the counts represent a moving distance of the X-direction of the coordinate input apparatus 1 at each sampling period. The moving speed of the X-direction at each certain sampling period of the coordinate input apparatus 1 is computed based on the moving distance/sampling period. The moving direction of the X-direction of the coordinate input apparatus 1 is obtained by checking the output pulse of the photo sensor 8 at each sampling period when measuring the moving distance and the phase difference of the output pulse of the photo sensor 9 and judging whether the rotation is the normal direction or the reverse rotation direction.
The moving speed and moving direction are detected with respect to the Y-direction in the same manner.
The thusly obtained moving speed and moving direction of the X-direction and Y-direction of the coordinate input apparatus 1 are inputted into a microcomputer(not shown), and the moving speed and moving direction of the coordinate input apparatus 1 are computed and then outputted.
In the conventional coordinate input apparatus, two shafts rotating based on a contact with the ball 2, two rotation circular plates having the slits, four sensors for measuring the rotation speed and rotation direction of two rotation circular plates are provided. Therefore, the number of components and the size of the product are increased.
Accordingly, it is an object of the present invention to provide a small-sized movable coordinate input apparatus which is well adapted to a conventional system for a movable coordinate input apparatus.
To achieve the above object, there is provided a movable coordinate input apparatus which includes a ball, and a cylindrical hollow ball holder wherein the ball includes an insulation portion formed in a net shape on a surface of the same and having a conductive characteristic, and the ball holder includes a ceiling plate on the top portion of the same, a conductive ceiling plate portion contacting with the ball when the ball holder is placed on a floor surface, and an angle sensor having an electrical resistance surface contacting with the ball on an inner surface of the ball holder.
A coordinate movement and moving speed are obtained by moving the ball holder in a state that the apparatus is placed on the floor surface.
A coordinate movement and moving speed are obtained by rotating a portion contacting with the floor surface of the ball using a finger.
The ball holder is formed in a cylindrical shape having a certain space therein in which the ball is movable.
The ball holder is formed in a polygonal cylindrical shape having a certain space therein in which the ball is movable.
The electrical insulation portion formed on the surface of the ball is formed in a rectangular net shape.
The electrical insulation portion formed on the surface of the ball is formed in a polygonal net shape.
The electrical insulation portion formed on the surface of the ball is formed in a circular net shape.
The electrical insulation portion formed on the surface of the ball is formed by filling an insulation material.
The electrical insulation portion formed on the surface of the ball is formed of a groove having a certain depth for thereby obtaining a non-contact with the ceiling plate and the angle sensor.